You are gapped twice.

Any lossy codec discard out information.

If your source is lossy like Spotify, you will have some generation loss due to its lossy codec.

If you use Bluetooth, again you are using a lossy codec. In case of PX7 and iOS, the only common codec is the mandatory SBC.

Sounds like a disaster. However, what you can do is take a couple of lossless files (ALAC as Apple don't like FLAC) and load them on your phone. Also transcode them to e.g. 256 AAC.

Do a listening test (preferably unsighted). Can you really tel the lossless and the lossy sources apart over Bluetooth? Would be surprised.

>You're capped at 256 kbps AAC-LC.

No, according to https://www.bowerswilkins.com/nl-nl/product/headphones/px7-s2 it is Bluetooth 5.2 met aptX™ Adaptive. So no AAC as it is not supported by the PX7 and no APTX as it is not supported by iOS hence SBC as the only common codec.

Its a matter of headroom.

The loudest you can play at the digital side is called 0 dBFS. If you exceed this level, you get digital clipping.

Often recordings do have sufficient headroom e.g. 10 dB so you can boost without hitting 0 dBFS. However, there are also recordings with very little or no headroom. This is typical for the loudness war. Even the slightest boost will result in distortion (digital clipping).

As already mentioned by others, a simple strategy is not boosting but lowering. If you want to emphasize 400-2400, leave them at 0 and lower the rest.

Another solution is simply not using the Spotify EQ or the EQ of any other app as you have to tailor each app. Just go system wide. https://www.audiosciencereview.com/forum/index.php?threads/eq-software-for-windows-linux-macos-ios-ipados-and-android.18450/

If it comes with a pre-amp, you can boost to your harts content and simply use the pre-amp to compensate for the highest boost. In case of Win you can also avoid distortion caused by resampling signals close to 0 dBFS.

Yes, one has a 3.5 mm TRS the other a 2.5

So one will fit in the earcup and the other won't.

As you do have the Sundaras, measure the current jack that go into the earcup. My guess is 3.5 https://hifiman.com/products/detail/286 but make sure before you order.

Have it terminated with a mini XLR and order a mini XLR to 4.4 pentagon as well.

The fun of the mini XLR is that Hart offers all kind of adapter making it possible to connect to anything https://hartaudiocables.com/collections/hacable-kit

Try https://www.bluetoothgoodies.com/tweaker/

One of the tests they use is establishing your hearing threshold for various frequencies (equal loudness contour). You can't do that reliable if you don't know the frequency response of the headphone. I presume it is calibrated just like you use a calibrated mic for measurements.

Looks like a pretty good audio interface to me: https://www.audiosciencereview.com/forum/index.php?threads/motu-m2-review-audio-interface.19911/

Nothing wrong with http://archimago.blogspot.com/ either.

> i don't understand this people

Why don't you keep it that way? Words are very inaccurate. Peoples impression are what they are, what they experience when listening to something. Not to be mistaken for the properties of the object listening to.

You might start your journey to insight here: https://www.stereophile.com/writer/15081

More recent: https://www.audiosciencereview.com/forum/index.php?pages/Reviews/

Indeed, educate yourself but if you do, select the right teachers 😀

Have a look here: https://www.reddit.com/r/headphones/comments/yepz6p/how_can_i_calculate_how_loud_a_set_of_headphones/

> the laptop is louder than my E10k on low gain.

If it is louder, you will hear more bass and more treble ( Google Fletcher Munson). A louder bass will mask the midrange.

Another might be a difference in output impedance. This will affect the damping. If the PC has a higher impedance, you get a less controlled bass. However, as the HD6xx is probably 300 Ohm, I wonder if the impact will be that big.

Most of the time if you have a mic, bluetooth switches to the headset profile delivering you 64 kbs mono sound.

Assuming you are talking Android, there is a systemwide EQ.

>Etymotic er4sr

Pretty neutral but a bit light in the bass department. Use the systemwide EQ to boost 100 Hz with 2 up to 3 dB. That is all you need IMHO.

The product you mentioned is uni directional, no mic.

Have a look here: https://avantree.com/aria-pro-2-headphones-with-microphone#spec-tab

However, I doubt you can connect 2 of them at the same time to a PC.

As they come with there own BT adapter, it might work. Better ask Avantree first.

"flat" and "neutral" are 2 different things.

Classical music are acoustical instruments and most of them are in the mid range.
A headphone with a V-shaped frequency response I do think totally unsuited for classical. The thundering bass masks the midrange. That piercing treble you won't find in real life. Go to a concert hall and listen to a symphony orchestra. Notice that you can hear contra bass and kettle drums but also note the level is low. Like wise a Steinway. Very big but very soft on the bass.
Basically, use EQ to tune your headphone to obtain a neutral response.

What is neutral? Often the Harman or the Sennheiser response is mentioned. Harman did some excellent research. They even found out who didn't like their curve. Bass heads think the bass to soft. Woman think the bass to loud and people over 50 think so to.
Evidently, it is a preference. https://audiosolace.com/harman-target-curve-explained/

Best you can do is calibrating your hearing. Visit live performances, preferably in a hall with good acoustics. This wil be your reference.
My practice is a sober one. Using Etymotic ER4P I boost the 100 Hz band with2-3 dB. Using HD800 I do exactly the opposite.

Great

> I like the looks of tubes

What about this one: https://wooaudio.com/amplifiers/wa7

>Sadly tubes don't give me as much bass as I expected. Like none at all even.

They shouldn't. A good amp simply amplifies, no salt and pepper added.

What can happen: tube amp often have a higher output impedance.

Combine this with a low impedance headphone and the damping ratio drops to much (headphone impedance/ amp headphone out impedance). This yields a bloated bass. Gladly you have a high impedance headphone (300 Ohm) so you won't have this problem.

I love cup D

>Dr.Dre

LOL, that is exactly what I had in mind, the original Beats with their 10 dB bass boost around 100 Hz.

Indeed, < 3 ms

https://www.shure.com/en-US/performance-production/louder/shure-whiteboard-digital-wireless-latency-explained#:~:text=Total%20System%20Latency&text=As%20mentioned%20above%2C%20a%20Shure,in%20your%20entire%20audio%20system.

>latency of my monitor

What monitor?

You have a headphone Bluetooth Tribit XFree Go

A PC with a dongle

A mobile with Bluetooth.

Things you can try

Another PC preferably one with build-in Bluetooth. If latency drops, it might be the dongle.

Another mobile, preferably a modern one. If we have to believe https://www.soundguys.com/android-bluetooth-latency-22732/ you should get < 30 ms.

So fool around a bit until you find the culprit.

Bluetooth latency is both hardware and software depended.

Codecs like SBC, APTX, etc. might have a latency of approx. 200 ms.

APTX-LL is the best (30 ms) but is replaced by APTX-Adaptive.

Old mobiles can even hit 500 ms, modern can do 20-40 ms regardless the codec.

Bit more about Bluetooth: https://www.thewelltemperedcomputer.com/HW/Bluetooth.htm

As a starter, have a look here, they offer TV listing sets so low latency: https://avantree.com/eu/

A matter of wiring.

If the headphone has 4 wires, it can be used "balanced"

If the wire is fixed to 1 cup, it is probably a 3 wire connection.

If it has a connecter to 1 cup and the plug is TRRS, it can be used balanced.

If it is a Y-cable with connectors, you can get a balanced cable.

Had a quick glance at the specs of the 50X90S.

It should have a optical (Toslink) out at the side.

Connect a DAC/headphone amp with optical input to it and you are fine.

You might need to dive in the TV menu to make sure the output is PCM only.